Python Chapter 7 Notes
Mathematical Order of Nature, Fall 2009

Decisions, Section 7.1 - 7.3

• The multi-way decision structure (section 7.3) is usually the best to use - make it your first choice until you see a better way.
• The convert2 (p202) warning program but with multi-way decisions
• A grading program grades.py (Ch2p2)

Comparisons, Section 7.1

• The comparison operators (p203) <, <=, > >=, ==, !=.
• The True and False values as results of comparison operations.
• Strings are compared lexicographically. The underlying ASCII number determines the order (along with the usual dictionary rules for ordering).

One-way Decisions, Section 7.1

• Sometimes handy, but don't use unless they fit.
• The add-on situation, overtime.py
• The over-writing situation, max3.py (p222), maxn.py (p223)
• The search and quit situation, find.py
• The Python program as module idiom (p205-206)

    if __name__ == '__main__':
           main()
  

Exception Handling, Section 7.4

• Use exceptions to check and report user input errors

• except ValueError:
• except NameError:
• except Typeerror:
• except SyntaxError:
• except:

Fibonacci

• Ch3p16 fib program
• Ch6p7 fib function
• fib recursion